What is macroecology?
Natalie Cooper (
natalie.cooper@nhm.ac.uk
)
2018-02-20
What is macroecology?
Macroecology is ecology at large spatial scales
What is macroecology?
What is macroecology?
Ecology at large scales
large spatial scale (explicit)
large temporal scale (implicit)
large numbers of species (broad taxonomic scale)
no clear definition of what scale defines macro vs. not macro
Why did macroecology emerge?
First use of the term is Brown and Maurer 1989 Science
Why did macroecology emerge?
First use of the term is Brown & Maurer 1989 Science
Experiments have limits
Scaling from local to global patterns is hard.
Ecological processes act at various scales.
“Seeing the forest for the trees” - Gaston & Blackburn 2000
Data availability (and analysis tools)
What do we study in macroecology?
Broad scale ecological patterns and the processes that underlie them
geographic range size
body size
abundance
diversity (species richness, functional diversity, phylogenetic diversity)
Species area-relationships
More area = more species (
Willis 1922
)
\(S = cA^z\)
(
Arrhenius 1921
)
Species area-relationships
More area = more species (
Willis 1922
)
\(S = cA^z\)
(
Arrhenius 1921
)
\(log(S) = z* log(A) + c\)
Species area-relationships
More area = more species (
Willis 1922
)
\(S = cA^z\)
(
Arrhenius 1921
)
\(log(S) = z* log(A) + c\)
\(z\)
is usually small (0.1-0.5)
\(z\)
may depend on many factors
type of species involved
climate
altitude
latitude
species interactions
Body-size diversity relationships
Right skew at large scales (
Brown & Nicoletto 1991
)
Normal distribution at small scales
Mechanisms varied
speciation and extinction rates
dispersal abilities
competition
energetic constraints
Hutchinson & MacArthur 1959
Abundance body-size relationships
Negative correlation (
Damuth 1981
)
Large animals have lower abundance
Mechanisms include species energy hypotheses
Macroecological “rules”
Bergmann’s rule (
Bergmann 1847
, see reference list)
warm-blooded vertebrate species from cooler climates tend to be larger than congeners from warmer climates
mechanisms include SA:Volume, energy requirements etc.
true for about 70% mammals, 60% birds (
Meiri & Dayan 2003
)
Macroecological “rules”
Allen’s “rule” (
Allen 1877
)
species have smaller extremities at high absolute latitudes.
Rapoport’s “rule” (
Rapoport 1982; Stevens 1989
)
species have larger ranges at higher absolute latitudes.
Gloger’s “rule” (
Gloger 1833
)
species are darker coloured nearer the equator.
Hotspots of biodiversity
Grenyer et al. 2006
Latitudinal diversity gradients
More species in the tropics than temperate zones.
True for most species (exceptions include marine mammals, bumblebees, turtles…)
Mechanism is still unclear…there are hundreds of hypotheses!
Why are there more species in the tropics?
Higher diversification rates (high speciation, low extinction)
Geographical area
Mid domain effect
Time for speciation
Historical perturbation
Climatic stability
Species-energy
Species interactions
Biases in counting species
Why is diverification higher in the tropics?
Weir & Schluter 2007, Jablonksi et al. 2006, Mittelbach et al. 2007, Schemske 2009
Bias in counting species
Small species may be missed
Species in complex habitats may be missed
Uncharismatic species may be missed (taxonomic bias) (
Isaacs et al. 2004
)
How do we study macroecology?
Mapping species distributions
Biodiversity indices (
Today
)
Phylogenetic comparative methods (
Monday
,
Tuesday
)
Large databases e.g. PREDICTS, PBDB (
Friday
)
Models, simulations etc.
Increasingly field work
Modern macroecology
Big data, big analyses, complex methods
More applied topics
disease macrecology
anthropogenic change
invasive species
climate change
land use change
More focus on mechanisms and models
Citizen Science (
Angela Marmot Centre
)
Data availability, sharing, reproducibility
Interested in learning more?
Twitter:
@BESMacroecol
Conference @ St Andrews 10-11th July
Macro ecology/evolution, paleo and living data (CPEG 30th Aug @ Leeds Uni)
